How to interrogate a Bluetooth LE device

Step 1

Please install the Light Blue app on your phone

iOS, Android

That’s a free app that lets you interrogate Bluetooth LE devices.

Step 2

As soon as you have it running, please turn on your Bluetooth device and make it read and share your HR/SpO2 data.

Step 3

After that’s done, start the Light Blue app. You should see your device in the list of bluetooth devices on the first screen.

Step 4

Connect to the device.

Step 5

Make a screenshot of the advertisement data.

Then scroll through the available services, make screenshots.

Step 6

Check if there are any characteristics marked as ’Notify’ (there are 3 possible values, Read, Write and Notify. We are interested in Notify ones).

Tap on the characteristic marked as Notify and try to make it stream the data (you’ll see Listen or Subscribe buttons, depending on your system). Make screenshots.

Step 7

If everything goes well, you’ll see hex data coming from the device.

Step 8

Export a log file and send it to me along with the taken screenshots

Here is a video demonstration: https://www.youtube.com/shorts/RMXR-BEfpgI

Please let me know if you have any questions.